In the trenching industry, earth may be degraded using picks or teeth to break up minerals and rocks. Picks are generally attached to chain driven assemblies and are used for excavating large amounts of hard materials. In trenching, a chain supporting an array of picks may rotate such that the picks engage a surface causing it to break up.
Examples of degradation assemblies from the prior art are disclosed in U.S. Pat. No. 6,824,225 to Stiffler, which is herein incorporated by reference for all that is contains discloses a rotatable cutting bit, and rotatable cutting bit holder assembly and washer that have increased wear resistance characteristics. The assembly incorporates a new holding washer design that has improved rotational characteristics between the cutter bit and top surface of the washer during operation.
U.S. Pat. No. 6,854,810 to Montgomery, Jr., which are all herein incorporated by reference for all that it contains discloses a wear sleeve in a cutter tool assembly that comprises a rearward split ring portion and an intermediate cylindrical ring portion adjacent a forward shoulder portion The outer diameter of the wear sleeve intermediate portion and rearward split ring portion is uniform. The wear sleeve is inserted into the bit holder's stepped bore aperture. The split ring portion is radially compressed by the smaller diameter rearward end as the sleeve is hammered and axially displaced into the bit holder.
The picks typically have a tungsten carbide tip. Efforts have been made to extend the life of these pointed inserts. Examples of such efforts are disclosed in U.S. Pat. No. 6,051,079 to Andersson et al., U.S. Pat. No. 5,417,475 to Graham et al., U.S. Pat. No. 6,733,087 to Hall et al., all of which are herein incorporated by reference for all that they disclose.